Treatment of carbonaceous materials



March 26, 1929. s Ru 1,706,468

TREATMENT OF CARBONACEOUS MATERIALS Filed Jan. 15. 1926 Patented Mar.f26, 1929.

UNITED STATES PATENT OFFICE.

TREATMENT OF CARBONAGEOUS MATERIALS.

Application filed January 15, 1926, Serial Ito/81,471, and in Great Britain January 26,.1925.

This invention relates to the treatment of solid carbonaceous materials and has for its object the production from such materials of products usually obtained as a result of the carbonization of the material in a retort and distilled until the last desired constituents boiling at a temperature below that of the carrier liquid have distilled off. One method of recovering the carrier which has been added to the" carbonaceous material,

under th di dry distillation condiafter the constituents of lower boilin point tions, but without having resort to such usual carbonization treatment.

According to the present invention a process for the distillation of solid carbonaceous materials consists-in subjecting to distillation a mixture of the carbonaceous material to be treated with a carrier comprising a substance having a higher boiling point than that of the products it is desired to obtain from the said material, whereby there is obtained a distillation product having a boiling point below that of the carrier.

As examples of the solid carbonaceous materialsthat may be treated by means of the present process there may be mentioned torbanite, oil shales, coal, brown-coal, peat, lignite, tar-sands, wood and woody-fibres, and the carrier added thereto before the mixture is subjected to distillation consists preferably of a body or bodies of generally similar char acter to one or other of the distillation products obtained by the ordinary processes of dry distillation of the carbonaceous material; the carrier is either a liquid at ordinary temperatures such as an oil or, whenit is desired to produce from the carbonaceous material constituents having a very high bolling point, the carrier to be added may be solid at ordinary temperatures,.such as a wax, being reduced to a liquid or viscous fluid in the course of heating it with the carbonaceous material.

Before treatment the carbonaceous material is crushed to a powder or broken to suitable siz'edlumps. It is then introduced into a still or other suitable distillation apparatus and a quantity of the liquid (or in certain circumstances solid) carrier of higher boiling 7 point than that of the products to be distilled,

which may amount to severaltimes that of the carbonaceous material, is mixed therewith. In the case for example of the treatment of torbanite so as to obtain therefrom. what ordinarily constitute the lighter fractions obtained in the usual distillation rocess, such as motor spirit, paraflin oil, and ight and medium lubricating oils, the torbanite has added thereto as carrier a liquid comprising the so-called heavy fractions obtained from the distillation of carbonaceous materia1s, whereafter the mixture is heated have distilled off, is to carry the distlllation I further (with or without the aid of steam and preferably in a different apparatus from that in which the first distillation is carried out) until the carrier added together with the constituents of approximately thesame boiling point derived from the carbonaceous material treated also distills off; the carrier together with any constituents derived from the carbonaceous material treated is of course then collectedseparately from the lower boiling constituents first obtained, and can be again used for treating a fresh batch of the carbonaceous material.

The following example is given by way of illustration of one suitable method for the distillation of torbanite or oil shale in accordance with the process of the present invention.

The torbanite or oil shale is crushed to a coarse powder and together with a carrier comprising a heavy oil or paraflin wax havin a boiling point of about 300 C. to 350 introducedinto a still, the relative proportions of the torbanite or oil shale and carrier being about one part by weight of the former to two to three partsby weight of the latter. The mixture is then subjected to distillation by heating it in a suitable apparatus and a mixture of oils ranging from light motor spirit to heavy oils with a boiling point of about 330 C. and containing a little of the carrier is obtained; this mixture can be regarded as approximating in composition to an ordinary crude oil obtained by distillation according to the ordinarymethods. By subjecting this mixture to fractional distillation, its separation into various light and heavy oils can be effected, or instead of collecting the products of distillation from the mixed torbanite or oil shale and carrier in one fraction, the fractions with boiling point between certain limiting ranges can be separately collected, and eachsuch fraction thereupon subjected to any further treatment desired. By this method there can be obtained a yield of mixed crude oils amounting to about 90 gallons per ton of torbanite, whereas by the ordinary dry distillation method the yield is only about 7 0 to 80 gallons of crude oils per on, which latter however are considerably inferior in quality, are of a somewhat higher specific gravit and contain more free carbon than the pro ucts obtained by the present process. In carrying out the distillation of the mixed torbanite or oil shale and carrier, it is preferred to collect separately the last portions of the heavy oils which distill ofi, namely those having a boiling point above about 290 (3., and to returnthese portions to the still (together with the carrier which may be recovered from the residual solid material in a manner referred to hereinafter) wherethey act similarly to the origlnal carrier 1n.

facilitating the distillation of the crude oils from the torbanite or oil shale, and also at the carrier originally added to the torbanite or oil shale and the heavy oil or wax obtained from its final heating, a residue of fine carbonaceous material being left. The carrier and products of a similar high boiling point so recovered can be utilized in the distillation of a fresh batch of torbanite, oil shale,.or

- other carbonaceous material, or for any other purpose desired. Instead of subjecting the whole of the residual material to a further.

heating as just mentioned, it can be withdrawn from the still and allowed to settle, the lighter portions being then returned to the same still for use in the process, whilst only the heavier portions are introduced into a second still wherein they are heated to considerably higher temperatures. Alternatively, instead of distilling the heavier portions, they can be split up into various lighter constituents by any suitable crackin process, or they can be submitted to a suitab e separation treatment whereby the oils and solid substances are separated from one another, the former of which may be again employed as carrier and the residual solidstreated as-a by-product or used as a fuel for supplying.

in the accompanying diagrammatic drawings in which 4 Figure 1 is a part sectional elevation, Figure 2 is a plan,

Figure 3 is a. section on the line 33-of Fi ure2and igure 4 is a section on the line 4-4 of Figure 1.

The crushed carbonaceous material, for example torbanite or oil shale, to be subjected to the distillation treatment is fed through the hopper a into the mixing pipe 6 in which it meets and is mixed with the carrier consisting of hot oil or li uid wax delivered from the pump a throug the pipe d; from the bottom of the mixing pipe I) the mixture of carbonaceous material and carrier passes into the still 0, heated in any suitable manner, in which it is continuously agitated by the rotatable blades or paddles f. The vapours produced during the distillation pass away through the various off-take pipes and thence to a condensing plant I; the various distillates may however be condensed and collected separately if desired. The residual materials consisting of solid carbonaceous materials suspended in the liquid carrier are delivered through the pipe 9 to the settling tank or'stand pipe h wherein the residual solid carbonaceous material settles out at the bottom and the liquid oil above it is drawn off through the pipe m and, after if desired passing through a heat interchanger n, returns to the pump 0 whence it is delivered again to thestill, the passage of the carrier and solid carbonaceous material suspended therein from the still a through the pipe 9 taking place as an ordinary hydrauhc flow under the circulating action of the pump 0. The solid material from the stand pipe is lifted through the elevator shaft 0 by a conveying device 0' such as a bucket conveyor of any suitable construction whence it is delivered through the pipe 10 to a second still g; whilst passing through the elevator shaft a considerable amount of the liquid adhering to the solid material runs back into stand pipe. The still g, wherein there are also provided rotatable blades or paddles f for the agitation of the materialtherein, is heated to a considerably higher temperature than the still 0, so as to drive off the carrier originally added to the carbonaceous material in the still e and products of a similar high boiling point obtained from the said carbonaceous material under the action of the hi h temperature. The distillates from the still 9 are taken oflz through the off-take pipes r whence they Bass to a condenser s from which they can be elivered to the pump a for reuse in the process, or utilized for any other desired purpose. The residue is discharged from the still g through a delivery valve 6.

It will be understoo that in carrying out the present process the distillates are collected and condensed in any usual manner,

and they maybe subjected to any desired process for further purification or fractionation, although such distillates are generall purer and not contaminated by other prod nets to thesame extent as those produced by the ordinary retorting methods.

The process according to the present intemperatures, whilst by a suitable choice of the methods heretofore in use for the production of distillationproducts from carbonaceous materials that the distillation can be effected at uniform and easily controllable the carrier added to the carbonaceous material dist-illates having a boiling point below a predetermined figure can readily be obtained. 1

What I claim and desire to secure by Let ters Patent of the United States is 1. A continuous process forthc distillation of solid carbonaceous material, such for example as torbanite, oil shales, coal, brown coal, peat, lignite, and tar sands, which comprises suspending the solid carbonaceous material to be treated ina comminuted form in a bath of a hydrocarbon carrier material maintained in bulk in an enlarged zone and having a'higher boiling point than that of the desired distillate of the carbonaceous ma terial, the relative-amount of'the hydrocarbon carrier being sufficient to maintain the solid material in mechanical suspension at the temperature of the distillation and to maintain such suspension in mobile condition during theoperation ofthe process, supplying heat directly to said zone and thereby subjecting the suspension without substantial alteration of the distillate or the carrier to free distillation at a temperature, as high as possible while being below that at which the bulk of the carrier normally distills, thereby obtaining a maximum yield of the desired distillation products having a boiling point lower than that of the carrier while distilling over a minimum amount of the carrier, agitating the suspension, removing the distillate, subjecting the solid carbonaceous material remaining undistilled together with associated hydrocarbon carrier to a settling treatment in a separate zone, thereby effecting separation of the hydrocarbon carrier, and returning the carrier to the bath.

-2. A continuous process for the distlllation of solidcai'bonaceous material, such for example as-torbanite, oil shales, coal, brown coal, peat, lignite,"and tar sands, Wl'llCh comprises suspending the solid carbonaceous material to be treated in comminuted form 1n a bath of hydrocarbon carrier material maintained in bulk in an enlarged zone and having .a higher boiling point than that of the desired distillate ofthe carbonaceous material, the relative amount of the hydrocarbon carrier being sufficient to malntain the solid material in mechanical suspension atthe temperature of the distillation and to maintain such suspension in mobile condition dur-= ing the operation of the process, supplying heat directly to said zone and thereby subjecting the suspension without substantial alteration of the distillate or carrier to tree distillation at a temperatureas high as possible while being below that at which the bulk of the carrier normally distills, thereby obtaining a maximum yield of the desired distillation products having a boiling point lower-than that of the carrier while distilling over a minimum amount of the carrier, agi-- tating the suspension, removing the distillate, sub c ct1ng the solid carbonaceous material remaining undistllled together with associated hydrocarbon carrier to a settling treatment in a separate zone, thereby effecting separation of the hydrocarbon carrier, continuously returning the carrier to the bath, and subjecting the residual solid carbonaceous material from the settling zone to further treatment for the recovery therefrom of hydrocarbon carrier still retained by such residual material. s

3. A continuous process for the distillation of solid carbonaceous material, such for example as torbanite, oil shales, coal, brown coal, peat, lignite, and tar sands, which comprises suspending the solid carbonaceous material to be treated in comminuted form in a bath of hydrocarbon carrier material main-- perature of the distillation and to maintain such suspension in mobile condition during the operation of the process, supplying heat directly to said zone and thereby subjecting the suspension without substantial alteration of the distillate or carrier to free dis- "tillation at a temperature as high as possible jecting the solid carbonaceous material. re-

maining undistilled together with associated hydrocarbon carrier to a settling treatment in a separate zone, thereby eflecting separation of the hydrocarbon carrier, continuously returning the carrier to the bath, Withdrawing the solid carbonaceous residue from the settling zone, draining oif the associated hydrocarbon carrier, returning'the' carrier so drained off to the settling zone, and subjecting the solid carbonaceous material to a seconddistillation at a'higher temperature than that employed for the initial distillation.

' 4; A continuous process for the distillation of solid carbonaceous materials as inclaim 1, in which there isiemployed a carrier consisting of a liquid hydrocarbon.

5. A continuous process for the distillation of solid carbonaceous materialsas in claim 3,

in which there is employed a carrier consisting of a liquid hydrocarbon.

7. A continuous process for the distillation of solid carbonaceous materials as in claim 1, in which there is subjected to distillatlon' about one part by weight of crushed oil shale suspended in two or threeparts by weight of a carrier comprising a liquid hydrocarbon solid carbonaceous material is subjected to distillation are condensed and returned to the first distillation zone for re-use as carrier in theprocess. I

tion of-solid carbonaceous material, such for example as torbanite, oil shales, coal, brown coal, peat, lignite, and tar sands, which comprises suspending the solid carbonaceous ma-' terial to be treated incomminut'cd form in a bath of a hydrocarbon carrier material maintained in bulk in .an enlarged Zone and having a higher boiling point than that of the having a boiling Point of about'3ooo \desired distillate of'the carbonaceous ma- 350 C. so as to obtain distillation products consisting of a mixture of oils ranging from light motor spirit to heavy oil.

use.

8. Acontinuous process for the distillation of solid carbonaceous materials as in claim 2,, in which there is subjected to v distillation about one part of crushed oil shale suspended Y in two to three parts by weight of a carrier comprising a liquid hydrocarbon having a boiling point of about 300 C. to 350 C. so as to obtain distillation products consisting of amixture of oils ranging from light motor spirit to heavy oil.

9. A, continuous process for the distillation of solid carbonaceous materials as in claim 3, in which there is subjected to the initial distillation in the first distillation apparatus about one part by weight of crushed oil shale suspended in two to three parts by we1ght of a carrier comprising a li uid hydrocarbon having a boiling point of a out 300 C. to 350 C. so as to obtaindistillation products consisting of a mixture of oils ranging from light'motor spirit to heavy oil. I

10. A continuous process for the distillation of solid carbonaceous materials as in claim 1, in which the heavier oils produced during the last stages of the distillation of the carbonaceous material in the bath of car- ,rier are collected separately and returned for re-use.

1 1. A continuous process for the distillation of solid carbonaceous materials as in claim 2, in which the heavier oils produced during the last stages of the distillation of the carbonaceous material in the bath of carrier are collected separately and returned for re- 12. A continuous process for the distillation of solid carbonaceous materials as in claim 3, in which the heavier o ils reduced during the last stages of the d1st1l ation of the carbonaceous materialin the bath of car rier in the first distillation zone are collected separately and returned to the aforesaid first distillation zone.

13. .A continuous process for the distillation of solid. carbonaceous materials as in claim 3, in which the distillates from the sec- 0nd distillation zonewherein the drained terial, the relative amount of the hydrocarbon carrier being sufiicient to maintain the solid material in mechanical suspension at the temperature of the distillation and to maintain such suspension in mobile condition during the operation of the process, supplying heat directly to said zone and thereby subjecting the suspension without substantial alteration of the distillate or carrier to heavier oils for re-use, withdrawing the residue whilst the said residue is in the heated condition and without having been previously cooled, subjecting the said residue so withdrawn to a settlingoperation in a separate zone so as to separate it into a lighter portion consisting of the liquid carrier and a heavier portion consisting of residual solid carbonaceous materials admixed with car rier, continuously returning the said lighter portion to the bath for re-use, draining the said heavier portion so as toremove therefrom as much of the adherent liquid carrier as possible and returning the liquid carrier so drained 01f for re-use, subjecting the drained heavier portion to a second distillation and 14. A continuous process for the distilla- I i heating it, Whilst continuously agitating it, i

ing the carrier so recovered and other products of about the same boiling point to the first distillation zone for re-use 1n the process.

ARTHUR MARINUS ALEXANDER STRUBEN. 

